Actually, HawkBlade, Strike explained this over Vent. You manually add a small number, say, 10, then highlight it and paste it in over and over. As you paste the smileys over and over, you do the math in your head. Once you get to the right number, write that number at the end and Viola! you have 10k smileys.

Seriously though, this is not a good idea, as HawkBlade is right, this is considered spamming according to the rules. Also, we have a record for number of smileys (Which we are due for another check) and its for adding smileys to posts, not spamming.